Biosynthesis and multifaceted roles of reactive species in plant defense mechanisms during environmental cues

Abstract

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are key components of plant metabolism, acting as cellular damage agents and essential signalling molecules. They play crucial roles in plant growth, development, and responses to environmental cues. This review clarifies their distinct and overlapping functions within plant signalling pathways. ROS and RNS are produced in organelles such as chloroplasts, mitochondria, and peroxisomes, where their concentrations are tightly regulated to balance signalling functions and prevent cellular damage. We explore their signalling roles, mechanisms underlying signal transduction, interactions across plant systems, and influence on plant stress responses. Evidence shows that ROS and RNS regulate adaptation to drought, salinity, pathogens, and herbivores. Advanced imaging techniques have enhanced our understanding of their cellular dynamics in redox signalling pathways, highlighting the need to balance their production and scavenging for optimal plant health. Understanding their biosynthesis, signalling, and interactions is crucial for unravelling their contributions to plant growth and resilience.